Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to the prior art by inclusion in this section.
To assist users in making accurate cuts, many saw devices are adapted to receive rip fences, also known as material guides or guide assemblies. FIG. 13 depicts a saw device in the form of a table saw that includes a known rip fence 30. The table saw 10 includes a base 12 that supports an enclosure 14. The enclosure 14 houses an electric motor having a shaft upon which a cutting tool, usually a blade 16, is mounted for rotation. A planar surface, commonly referred to as a table 18, is secured to the top of the enclosure 14. The table 18 is usually constructed of a rigid and flat material such as metal, plastic, or fiberglass. The blade 16 projects through an opening 20 in the surface of the table 18. A first fence guide or rail 22 is located toward a front of the table 18 and a second fence guide or rail 24 is located toward a rear of the table 18. The guides 22, 24 can be formed as part of the table 18 or can be separate parts each of which is coupled to the table 18 at the appropriate location.
The rip fence 30 has a clamping system with a first clamp mechanism 32 and a second clamp mechanism 34 that are selectively moveable between a clamped position and an unclamped position. When in the clamped position, the first and second clamp mechanisms 32, 34 engage the guides 22, 24 in such a manner that the fence 30 is fixed in place with respect to the blade 16 and the table 18. When in the unclamped position, the first and second clamp mechanisms 32, 34 disengage entirely from the guides 22, 24 such that the rip fence 30 is free to slide along the table surface. The guides 22, 24 are constructed of a rigid material such as metal or plastic. The guides 22, 24 typically include grooves or other geometric structures that permit the rip fence 30 to be easily attached to and removed, and also permit the fence 30 to slide across the surface of the table 18 for positioning by an operator or user of the table saw 10.
While clamping systems such as that described with reference to FIG. 13 can adequately secure the rip fence to the table, some users find that the position of the rip fence can be moved out of alignment when the fence is clamped to the table. If the rip fence does move during clamping, the clamped location of the fence causes the material being cut to be cut along a line different than that intended by the user. This shift can result in an inaccurate position and angle for the rip fence, which can further result in an inaccurate and unsafe cut. Another issue with known rip fences is that when the position of the rip fence is adjusted, the rip fence can chatter or bind on the guides of the table due to insufficient biasing and loss of contact between the rip fence and the guides. Similar chattering, binding, and/or dislodgment can occur when the user moves these known rip fences from their rear end.
In view of the foregoing, it would be advantageous to provide a rip fence for a table saw where the rip fence provides for increased accuracy in cutting of material. It would also be advantageous if the rip fence could be self-aligned to the table while the position of the fence is adjusted along the table surface. Furthermore, it would be advantageous if the rip fence remained in its desired location when the rip fence is clamped into position on the table.